SSE said warned against "unintended consequences" of Government intervention in the sector, which It said was already "intensely competitive".

It said the introduction of a price cap could affect 4.76 million of its 6.76 million customer accounts.

SSE chief executive Alistair Phillips-Davies said: "We have been clear for some time that 2017/18 presents challenges, and the need to engage constructively with a new UK government as it takes forward energy policy will be a key priority for the year ahead and beyond."

Big Six rivals E.On, Centrica - owner of British Gas - and Scottish Power have spoken out against the price cap proposal, warning it could lead to higher bills for consumers and reduce competition.